Alion, Spectacle, Endaziflam, and Rejuvra all have the same active incredient indaziflam in the bottle. Indaziflam is registered for application to residential and commercial areas (lawns, ornamentals, and hardscapes including patios, walkways, etc.), turf (parks, cemeteries, golf courses, sod farms, sports fields, and commercial lawns), field-grown ornamentals, and Christmas trees, commercial nursery and landscape plantings, and forestry sites. Food use sites include woody trees, shrubs, vine fruits, and nuts. One of the first labels for indaziflam was actually in orchards. I'm pretty sure they are using it over seedling pine trees to restore logging areas in Oregon and Washington. There are bareground applications with indaziflam tank mixes that I would definitely keep away from trees!
We've been spraying over and under ponderosa pines and junipers without any injury in our area. In fact, the needles, cones, and trees themselves are considerably healthier than when there was cheatgrass in the understory. I'm hoping in the near future to collect growth ring data from the trees inside and outside of where we've controlled cheatgrass. We know exactly what year we controlled cheatgrass and my guess is the yearly growth ring gaps will be considerably larger after cheatgrass is controlled.